2003 Cayenne S- Harsh downshift HELP

[kirk7]

Hi there,

Need some advice.

Has anyone experienced some intermedient harsh downshifts...usually happens when i'm overtaking and going up a gradient from 5 or 6th gear into 3rd or 4th gear.

The car shutters a little. Any fixes? I'm taking it into a porsche workshop and would like to get some insight.

Thanks in advance.

Kirk

[Loren]

MY03 has a TSB for some hard shifting but it was in the 1st to 2nd range.

The solution was a new Tiptronic controller - you might check with your dealer and see if your car got the new controller.

[wvicary]

I think there is a new software version for the transmission for poor shifting, I would also check the driveshaft centre brng for any play.

[shastamonk]

Our 04 S had the same problem. Dealer replaced the valve guide assembly in the transmission.

Regards,

Scott

[PTEC]

There is a known issue for hard shifting from 5-4 or 5-3. Pay attention to which gears you're in when you feel it. If this is your problem you'll need a new valve body in the transmission. They're not cheap.

[rummelld]

I have had both repairs done for the harsh shifting on my 04 Cayenne S, here was my take away and diagnosis:

First issued appeared around 55k miles:

Harsh shifting in lower (1/2) gears. This lead to replacing the valve guide assembly, a costly repair around $2000.

I noticed this was in the transmission, look at the screen to see if it happens when gears are changing or just prior.

I just got the car back from the shop at 75k miles. I had intermittent studdering when the vehicle would be in 5/6 at a speed of around 35-40 and I eased on the gas. The car would studder/soft backfire (not shift) and then eventually downshift and accelerate like normal. I could prevent this from happening if I used the tiptronic to downshift prior to putting the car under load in 6th gear. The shop replaced the ignition coils for around $500.

The car now rides as smoothly as it did when it came off the lot. It seems that these are the two culprits for the harsh shifting (at least reported so far).

[gjameson]

I have the same problem with a 2003 model S. Downshifting from 5th to 4th shudders 70-80% of the time.

I took it in to a Porsche place to try a gearbox oil change first. I just picked it up and its skipping gears all over the place!

He said could be air bleeding out of the system, and to try it over the weekend. If this doesn't fix the problem

we will have to change valve assembly if he can buy it here in the UK.

Anyone have any insight into this huge problem?

:renntech:

I love this forum!

Was just test driving it again and when I came to a complete stop, it down shifted to Neutral and

the engine light came on! The display that shows the gears now is a constant D.

Oh this is going to drive me crazy!

Edited May 8, 2009 by gjameson

[Reborn996]

I just had this fixed on my 04 CTT... it was the valve body in the transmission. We also replaced the trans control unit as they said it would need to be matched to the new valve body. Already did the coil packs previously. Works great now! I would recommend Suncoast or Sunset for getting the parts online if a local mechanic can't source them. David

[SYongo]

Hi there,

Need some advice.

Has anyone experienced some intermedient harsh downshifts...usually happens when i'm overtaking and going up a gradient from 5 or 6th gear into 3rd or 4th gear.

The car shutters a little. Any fixes? I'm taking it into a porsche workshop and would like to get some insight.

Thanks in advance.

Kirk

I'm in Africa and I'm experiencing the same thing with my 2004 porche cayenne s. Please let me know if you could find any fix.

[boinging]

I'm another one who had this problem, fix is a Valve Body replacement.

The drive is now much smoother.

[horstle]

There is a known issue for hard shifting from 5-4 or 5-3. Pay attention to which gears you're in when you feel it. If this is your problem you'll need a new valve body in the transmission. They're not cheap.

I changed both the valve chest and the coils - is it possible that the mount of the cardan shaft or some bearing broke?

regards